Artificial limb.



F. H. CRITCHLEY.

ARTIFICIAL LIM B;

7 APPLICATION FILED JINE Is. 1918.

mama Patented. Oct. 29, 1918.

a SHEETS-SHEET I F. H. CRITCHLEY. ARTIFICIAL LIMB.

APPLICATIQN FILED JUNE 13. 19H}.

Patefited 0st, 29, 1918 2 SHEETS-SHEET 2.

FREDERICK HAROLD CRITCHLEY, F LIVERPOOL, ENGLAND.

ARTIFICIAL LIME.

Specification of Letters Patent. 7 Patentgd @0113. 29, new.

Application filed June 13, 1918. Serial No. 239,778.

To all whom it may concern:

Be it known that I, Fnnonnrox HAROLD Cnrronnnr, a subject o'f'the King of Great Britain, and a resident of Liverpool, Eng land, have invented certain new and useful Improvements in Artificial Limbs, of which the following is a specification.

This invention relates to improvements in artificial limbs and is particularly dirooted to the-manufactureof artificial legs. The great disadvantage in the present construction of artificial le s arises from the fact that the knee-joint w ile limited against rearward closing movement is quite free to close by forward movement, and consequently should the weight of the wearer be thrown on the leg when the-knee-joint is in a flexed position, a collapse of the artificial limb is inevitable, and where provision has beenv made to obviate this, such as by fitting pieces of elastic material, it is not satisfactory, the elastic material being insuflicient to prevent collapse of the jomt under the weight ofthe wearer. In the action of walking, however, when the artificial limb is thown forward the knee-joint should be slightly flexed and provision should be made for preventing the forward collapse of the limb when the weight of the wearer comes on the knee-joint and. the object of the preselpt invention is to provide means to insure t is.

An artificial leg in accordance with this invention is shown in the accompanying drawings, in which Figure 1 is an elevation partly in section, showin the leg slightly flexed atthe knee-joint, Flg. 2 being a fragmentary detail showing the knee-jomt pivot in outside view, Fi 3 a cross section through the knee portion of the leg showing the joint in end wow, and Fi 4. a perspective view of the detachable ru ber toe piece for the foot. Fig. 5 is an outside view. of the leg corresponding to Fig. 1, Fig. 6 being a section on an enlar ed scale ofthe knee joint pivot and Fig. a cross section of the pivot in a plane at right angles to Fi 6.

. l n carrying out the invention, a skeleton framework ofmetal is built up consisting of ailowertubular or'like element 1 in the calf portion of the leg pivotally connected at the knee to straps or the like pieces 2 in the thigh part of the leg. 'The tubular element 1 is pivotally connected at 3 to the foot piece 4, say, by means of looped rods 5 passin around grooved rollers 6. The knee joint is formed in the manner of a barrel 7 carried from and held a ainst rotation by the straps 2 and adaptec? to be frictionally grlpped'by a hand brake, the band '8 of which, while normally loose when the weightof the wearer is not on the limb is adapted to be tightened about the barrel 7 by the downward pull of a rod 9 pivotally connected at 10 to the heel part of the foot piece 4, the upper end of the rod passing throu h split ugs 11 on the bands, a nut 12, w en the rod 9 is drawn down, contracting the band 8 about the barrel, so preventing relative rotary movement between the band and the barrel lockin the joint. The band 8 is rigidly fixed an carried at the to) of the tube 1, and the barrel being carrie by'the straps 2, the arrangement forms an eas pivotal joint oifering a large wearin sur ace. The foot piece 4 being pivotc to the tubular element 1 at 3, when the weight of the wearer is thrown on the toe of the foot piece the latter tends to turn about the pivot 3, drawing down the rod 9 which, by pressing on the upper lug 11 contracts the and 8 on-the barrel 7 and locks the joint. In this way no matter what the flexion of the knee joint forwardly, the leg as a whole cannot eollapse'about this joint even thou h it carries'the full weight of the wearer. hen the leg is lifted, the knee joint will, however, a ain become loose, and the lower part of the leg free to swing. The band 8 normally tends to 0 en and free itself by its own resilience, t e lugs 11 being then slightly open, and if desired a compres sion sprmg 13 may be fitted bearing against a collar 14 on the rod 9 and the head of a sleeve 15 on the rod adapted to take the thrust of the spring against the lower lug 11. The function of this sprin 13 is to keep the nut 12 in close contact w1th the upper lug 11, thus preventing any lmock or jar when the pull comes on the rod 9, the action of such sprin 13, however, not being strong enough to lock the knee oint. In this Way the knee joint is normally loose as the leg is thrown forwardin 'the action of walking and when not bearing the weight of the wearer, but directly the foot piece bends about the ankle pivot 3 due to the weight of barrel 7 and a slot 21 is formed in the barrel through which the pin 16 projects, the pin'traveling in the slot as the band 8 rotates. The slot 21 is carried halfway through the sockets 20 so as to leave the rubber rods 19 exposed for contact with the pin 16 as the lower part of the leg swings angularly to its limits. The barrel 7 is inclosed by a spigoted cap 22, and the straps 2 of the thigh piece are socketed to the barrel 7 and its cap '22 within ribs 23, the pivotal bolt 24 and the inner side cheeks of the thigh piece.

25 holding the straps'in engagement. The tubular element 1 and the straps 2 carry the molded limb portions (1, b, of the calf and thigh, respectively, which limb portions, as they do not carry any of the weight of the wearer, may be made out of light sheet metal, papier mach, or wood or molded out of suitable material, and may be made extremely light with a resulting advantage in the total weight of the limb. A detachable toe piece, Fig. 4:, is provided of rubber, this toe piece 26 having a s igot 27 which is entered into a correspond ing socket in the foot piece 4:, a sole 28 passing beneath the foot piece and the heel projection 29 entering into a socket, so that by attaching the heel by a screw 30 the whole toe piece is retained in place.

The strap pieces 2, as shown in Fig. 3, are bent outward and brought on the outside of the bucket part of the thigh piece, and they may be braced at their upper ends by a rear metallic strap 31. The leg may be attached to the wearer in any suitable or known manner, such as by the buckles 32 connecting up to any form of braced suspension, or otherwise, and the bucket is fitted with the usual lacing 33. The calf may be built in two parts about the tubular element 1 dowel'ed at 33 and held together by a bolt 34:, the calf parts a being supported from the element 1 by pins 35.

With such a construction besides the ad'- vantage that the leg thou h flexed becomes rigid when supporting t e weight of the 'wearer; owing to the fact that-the weight 60.

is carried by a metallic framework and not by the material of which the leg is shaped, the metallic framework and the molded or otherwise formed leg portions may be stand- -and calf pieces and normally loose, and a 1. In an artificial limb,-a thigh piece, ,a I

calf piece, a knee joint coupling the thigh pivoted foot piece, a connection between the foot piece andknee joint wherebythe p1v-,

otal movement of the foot piece coacts t lock the knee joint against flexure. 2. In an artificial limb, a thigh piece, a calf piece, a knee joint comprising a barrel element carried from one part of the limb co-acting with a brake band carried from the other part of the limb, said band being normally loose about the barrel, but contractible thereon to lock the joint when weight or end thrust is thrown on the limb.

3 In an artificial limb, a thigh piece, a

calf piece, a knee joint comprismg a barrel element carried from one part of thelimb co-acting with a brake band carried from the other part of the limb, said band being normally loose about the barretam a'piv-' oted foot piece, a connection between the foot piece and knee joint whereby the pivotal movement of the foot piece coactsto contract the band on the barrel and lock the knee joint against flexure.

4:. In an artificial limb, a thigh piece, a calf piece, a knee joint comprising a barrel element carried from one part of the limb co-acting with a brake iband carried from the other part of the limb, said bandv being normally loose about the barrel, a pivoted foot piece, and a pull rod connected to the pivotal movement of the foot piece acting to contract the band on the barrel and lock the knee joint against fiexure.

5. In an artificial limb, a thigh piece, a calf piece, a knee joint comprising a barrel element carried from one part of the limb co-acting with a brake band carried from the other part of the limb, said band being normally loose about the barrel, a pivoted foot piece, a pull rod connected to the heel ice heel of the foot piece engaging the band,

of the'foot piece engaging the band, and

a spring keeping the pull rod in close en- 5 gagement with the band,'pivota1 movement a of the foot piece acting to-contract the band on the barrel and lock the knee joint against flexure. j e 6. In an artificial limb, a thigh" piece, a

calf piece, a knee joint comprising a barrel element carried from one part of the limb co-acting with a brake band carried from the other part of the limb, said band being normally loose about the barrel,,a pin projecting from-the band traversing a slot-in I the barrel, a cushion abutment'at each end 1 ofthe slot adapted to silence the impact of 1,283,093 r I m the pin, and a pivoted foot piece, pivotal movement of the foot pieceacting to contract the band on the barrel and lock the knee joint against flexure.

7 In an artificial limb, a skeleton frame work by means of which the various parts of the limb are articulated together and which takes the weight of the wearer, and molded or shaped limb pieces which do not take the Weight of the wearer but are merely 10 attaizhed to and supported from the framewor a.

In testimony whereof I afiix my signature in presence of two witnesses.

t FREDERICK HAROLD GRITCHLEY.

Witnesses: A. J DAVIES, J. MCCORMICK. 

